Love it or loathe it, clay court tennis is the modern surface in Europe.
Spanish left-hander Rafael Nadal has maintained his stranglehold over Roger Federer by sticking to what he knows best on the dirt.
But what is it that makes the clay courts so different to grass and hard courts?
Clay is as natural a surface as you are going to get in tennis. It comes from naturally formed rock which is sometimes processed.
At Roland Garros the surface is made up of natural clay covered with crushed brick as a fine surface dressing.
It is this layer that gives the ball extra grip when it hits the deck, making the surface characteristically slow.
For example if the ball hits a clay court at 108 km/h it will typically bounce up at a speed of 64km/h. This is only 59% of its initial speed, making it a good deal slower than on acrylic (hard) or grass courts.
But the crushed brick also allows players to slide across the surface. It acts like ball bearings between the hard under layer and the player's shoe.
THE EFFECT ON THE BALL
Spanish clay court players are renowned for playing shots with heavy top spin to make the most of the grip on the court.
As a result the ball kicks up high and many shots are played at shoulder height making it difficult to hit winners.
BBC tennis commentator Andrew Castle says: "You can see the spin coming off the opposition's racquet on clay so if it's sliced, it's going to stay low, if it's top spin it's going to kick up. Spin is exaggerated.
"But clay can change a great deal. If you've just had a bit or rain and the surface is a bit moist the balls will pick up water and they'll be come heavy.
"That slows the ball down even more making it very hard to hit winners.
"On the other hand if it's hot and sunny and you've got a nice dusty court then the ball will zip through like a harder surface.
"So you need to be flexible and patient on clay. Sometimes you need to grind it out. You aren't going to hit any winners unless you're a brutal hitter of the ball."
THE EFFECT ON THE PLAYER
The high looping ground strokes you see on clay give players time to reposition themselves during a rally which are often 10-15 strokes in duration.
This hands an advantage to players with incredible power endurance - the ability to repeat short bursts of power over a long period of time.
Guillermo Coria has perfect footwork for the clay court
But quick and nimble players like Argentina's Guillermo Coria have the advantage according to Castle.
"The big deal on clay is your footwork," he says. "The movement is different because you must time your slide which can be anything up to two metres.
"Of course if you don't slide at all you can't get back to cover the court and you'll be out of position. It can be the difference between winning and losing a point.
"Many players use an open stance and often your foot is planted on the floor because of the loose nature of the surface. You really need to be flexible in your movement and quick adjustment."
CLAY COURT TACTICS
Champions on other surfaces have struggled to get their tactics right on clay.
Jimmy Connors, John McEnroe, Boris Becker and Pete Sampras are all linked by the fact they never won the French Open.
Andre Agassi however managed to buck the trend by taking the ball early and keeping his opponent on the back foot.
Castle says: "You need to dictate otherwise you're doing all the running, all the moving and the slipping and sliding.
"There's no surface which takes a drop shot better. You need to work every rally before you can open up the court for a winner.
"It's a real art form to be a good clay court player. That's why in general clay-courters don't usually win hard court tournaments."